Waterproofing system

ABSTRACT

A waterproofing system including a functional layer S 1  including 10-80 wt.-% of at least one thermoplastic polymer P 1  and 10-80 wt.-% of at least one solid particulate filler F, wherein the surface of the functional layer S 1  has an Auto-correlation length of waviness W(Sal) of at least 50 μm. Further, a method for producing a waterproofing system and to the use of a mechanical surface treatment step to increase the waviness factor, determined as the ratio of the Root mean square roughness of waviness W(Sq) to the square of the Auto-correlation length of waviness W(Sal), of a surface of a functional layer S 1.

TECHNICAL FIELD

The invention relates to waterproofing system for use in theconstruction industry, for example for basements, roofing and tunnelingapplications to protect concrete structures against water penetration.

BACKGROUND ART

Waterproofing systems consisting of waterproofing membranes are commonlyused in the construction industry for sealing bases, undergroundsurfaces or buildings against water penetration.

State-of-the-art waterproofing membranes are monolayer or multilayersystems comprising at least one polymer-based barrier layer to providewatertightness. Typical polymers used in barrier layers includethermoplastics such as plasticized polyvinylchloride (p-PVC) andthermoplastic polyolefins (TPO) or elastomers such as ethylene-propylenediene monomer (EPDM) and crosslinked chlorosulfonated polyethylene(CSPE). One of the drawbacks of polymer-based barrier layers is theirpoor bonding properties; they typically show low bonding strength toadhesives that are commonly used in the construction industry, such asepoxy adhesives, polyurethane adhesives, and cementitious compositions.Therefore, a contact layer, for example, a fleece backing, is typicallyused to provide sufficient bonding of the polymer-based barrier layerand the structure to be waterproofed.

In waterproofing applications, the membrane is typically post-applied toan existing concrete structure. In this case the membrane is bonded withan adhesive or a sealing tape via its contact layer to the surface ofthe concrete structure to be waterproofed. In pre-applied waterproofingapplications, however, the membrane is laid out before the concretestructure to be waterproofed is built. In this case, the membrane isplaced with its barrier layer against an underlying structure orformwork and fresh concrete is then cast against the surface of thecontact layer, thereby fully and permanently bonding the membrane to thesurface of the hardening concrete.

In pre-applied waterproofing applications, typically an adhesive isused, to bond the barrier layer to the contact layer and to the freshconcrete cast against the contact layer. The adhesive should also enablethe fresh concrete to penetrate deeply into to contact layer beforehardening in order to provide high resistance to penetrating water.

One of the main challenges related to the multilayer waterproofingmembranes is to ensure watertightness after infiltration in case of leakin the barrier layer. Watertightness after infiltration means in generalthat the sealing construction should be able to prevent the infiltratedwater from penetrating to the space between the membrane and thewaterproofed surface. A leak in the barrier layer can be a result ofinward growing tree roots, material failure or tensile or shear forcesdirected to the membrane. If the watertightness after infiltration islost, water is able to flow laterally underneath the membrane and toinvade the interior of the building structure. In such cases the exactlocation of the leak in the barrier layer is also difficult to detect.

U.S. Pat. No. 8,793,862B2 describes a waterproofing membrane comprisinga barrier layer, a composite layer arranged on one side of the barrierlayer and a network of sealant between the barrier layer and thecomposite layer. The network of sealant is said to limit the size ofarea affected by penetrating water in case of water leakage in thebarrier layer. In waterproofing applications the membrane is applied ona subsurface in such way that the barrier layer is directed against aconcrete base and the composite layer is facing the concrete castedagainst the membrane. During the hardening process, the composite layeris penetrated by the liquid concrete forming a good bond with thehardened concrete.

US2015/0231863A1 discloses a waterproofing membrane including a barrierlayer and a functional layer including a thermoplastic polymer thatchanges consistency under influence of highly alkaline media and anadhesive. Once the functional layer gets into contact with liquidconcrete, the thermoplastic polymer dissolves and allows the adhesive tobond to the cast concrete. The functional layer may additionallycomprise other thermoplastic polymers, fillers or concrete constituents.The construction of the functional layer is said to enable working withmembranes in adverse weather conditions without diminishing the adhesivecapacity of the membrane.

One disadvantage of state-of-the-art multilayer waterproofing membranesis related to the use of adhesives, which increases the complexity ofthe membrane build-up and consequently the production costs of suchmembranes. The adhesive has to provide good binding to the low surfaceenergy polymers in the barrier layers, form a strong bond to the contactlayer and to fresh concrete and have a good resistance to varyingtemperature ranges, UV irradiation and oxidation. Adhesives fulfillingall the requirements, if available at all, are expensive and thusincrease the production cost of such membranes by a significant amount.

Another disadvantage of state-of-the-art multilayer waterproofingmembranes is related to the use of fleece backings as contact layer toprovide sufficient bonding between the membrane and the substrate to bewaterproofed. In waterproofing and roofing applications the adjacentmembrane sheets have to be homogenously joined to each other in areliable way to ensure watertightness of the sealing construction.Membranes having a fleece backing cannot be joined by heat welding butinstead the edges of the membranes have to be bonded together eitherwith an adhesive or with a sealing tape adhered on top of the seamand/or under the seam. The use of an adhesive or a sealing tape to joinadjacent membrane sheets complicates the installation process andincreases application costs.

SUMMARY OF THE INVENTION

The objective of the present invention is to provide a waterproofingsystem, which can be used to protect surfaces against water penetration,for example in basement waterproofing, roofing and tunnelingapplications, and which fully and permanently bonds to concrete andother cementitious compositions cast onto the waterproofing system afterhardening, as well as to adhesives commonly used in the constructionindustry.

Another objective of the present invention is to provide a waterproofingsystem, which retains watertightness after infiltration in case of aleaking barrier layer.

It was surprisingly found that a waterproofing system comprising afunctional layer S1 comprising at least one thermoplastic polymer P1 andat least one solid particulate filler F dispersed in a continuousthermoplastic phase comprising the at least one thermoplastic polymer P1and having a certain surface roughness, is able to solve or at leastmitigate the problems related to State-of-the-Art waterproofing systems.

The subject of the present invention is a waterproofing system asdefined in claim 1.

One of the advantages of the claimed waterproofing system is that itprovides full and permanent bonding to cementitious compositions andwatertightness after infiltration.

Other aspects of the present invention are presented in otherindependent claims. Preferred aspects of the invention are presented inthe dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-section of a waterproofing system of the presentinvention comprising a functional layer S1 and a barrier layer S2.

FIG. 2 shows a cross-section of a waterproofing system of the presentinvention comprising a first functional layer S1, a second functionallayer S1′ and a barrier layer S2.

DETAILED DESCRIPTION OF THE INVENTION

The subject of the present invention is a waterproofing systemcomprising a functional layer S1 having a first major surface and asecond major surface, the functional layer S1 comprising:

a) 10-80 wt.-%, preferably 25-75 wt.-%, of at least one thermoplasticpolymer P1,

b) 10-80 wt.-%, preferably 25-75 wt.-%, of at least one solidparticulate filler F, said proportions being based on the total weightof the functional layer S1, wherein

in the functional layer S1, the particles of the at least one solidparticulate filler F are dispersed in a continuous thermoplastic phasecomprising the at least one thermoplastic polymer P1,

and wherein at least one of the first and second major surfaces of thefunctional layer S1 has an Auto-correlation length of waviness W(Sal),determined by means of the method cited in the description of at least50 μm, preferably in the range of 100-1500 μm.

The term “polymer” designates a collective of chemically uniformmacromolecules produced by a polyreaction (polymerization, polyaddition,polycondensation) where the macromolecules differ with respect to theirdegree of polymerization, molecular weight and chain length. The termalso comprises derivatives of said collective of macromoleculesresulting from polyreactions, that is, compounds which are obtained byreactions such as, for example, additions or substitutions, offunctional groups in predetermined macromolecules and which may bechemically uniform or chemically non-uniform.

The term “cementitious composition” designates concrete, shotcrete,grout, mortar, paste or a combination thereof. The terms “paste”,“mortar”, “concrete”, “shotcrete”, and “grout” are well-known terms inthe state-of-the-art. Pastes are mixtures comprising a hydratable cementbinder, usually Portland cement, masonry cement, or mortar cement.Mortars are pastes additionally including fine aggregate, for examplesand. Concrete are mortars additionally including coarse aggregate, forexample crushed gravel or stone. Shotcrete is concrete (or sometimesmortar) conveyed through a hose and pneumatically projected at highvelocity onto a surface. Grout is a particularly flowable form ofconcrete used to fill gaps. The cementitious compositions can be formedby mixing required amounts of certain components, for example, ahydratable cement, water, and fine and/or coarse aggregate, to producethe particular cementitious composition.

The term “fresh cementitious composition” or “liquid cementitiouscomposition” designate cementitious compositions before hardening,particularly before setting.

The term “particle size” refers to the area-equivalent sphericaldiameter of a particle. The particle size distribution can be measuredby laser diffraction according to the method as described in standardISO 13320:2009. For determination of the particle size distribution, theparticles are suspended in water (wet dispersion method). A Mastersizer2000 device (trademark of Malvern Instruments Ltd, GB) can be used inmeasuring particle size distribution.

The “amount or content of at least one component X” in a composition,for example “the amount of the at least one thermoplastic polymer P1”refers to the sum of the individual amounts of all thermoplasticpolymers P1 contained in the composition. For example, in case thecomposition comprises 20 wt.-% of at least one thermoplastic polymer P1,the sum of the amounts of all thermoplastic polymers P1 contained in thecomposition equals 20 wt.-%.

The functional layer S1 is preferably a sheet-like element having afirst and a second major surfaces defined by its peripheral edges. Theterm “major surface” refers in the present document to the top andbottom surfaces of such sheet-like elements.

Preferably, the functional layer S1 comprises a heterogeneous mixture ofat least two discrete phases, in particular a continuous thermoplasticpolymer phase and a discontinuous solid filler phase. The continuousthermoplastic polymer phase comprises the at least one thermoplasticpolymer P1 and optionally one or more other polymer materials and/oradditives that can be mixed or interspersed sufficiently with the atleast one thermoplastic polymer P1 so as to essentially constitute asingle “thermoplastic polymer phase”. The thermoplastic polymer phase ischaracterized as generally being capable of forming a melt by heating toabove a specified temperature and then re-solidifying when cooledsufficiently. Due to the presence of the thermoplastic phase, thefunctional layer S1 is weldable with other layers comprisingthermoplastic polymers, which are compatible with the at least onethermoplastic polymer P1.

The discontinuous solid filler phase comprises the at least one solidparticulate filler F, which may be present in the functional layer S1 asindividual particles or as aggregates of one or more particles. Theseare at least partially, preferably completely surrounded by thecontinuous thermoplastic phase. In case the functional layer S1 containsone or more mineral binders, such as cement, it is essential that thesedo not form interconnected solid networks of hydrated mineral binders.It may be preferable that the functional layer S1 is essentially free,more preferably completely free, of interconnected solid networks ofhydrated mineral binders. The particles of the at least one solidparticulate filler F will not generally undergo a phase change to form amelt. Instead, the particles will remain as a discrete discontinuoussolid phase interspersed throughout and among the continuousthermoplastic phase.

Preferably, the functional layer S1 comprises a homogeneously mixedmixture of the continuous thermoplastic polymer phase and thediscontinuous solid filler phase. A “homogeneously mixed mixture” refersin the present document to compositions, in which the individualconstituents are distributed substantially homogeneously in thecomposition. A homogeneously mixed mixture of a thermoplastic phase anda solid filler phase refers, therefore, to compositions in which theconstituents of the solid filler phase are homogeneously/uniformlydistributed in the thermoplastic polymer phase. For a person skilled inthe art it is clear that within such mixed compositions there may beregions formed, which have a slightly higher concentration of one of theconstituents than other regions and that a 100% homogeneous distributionof all the constituents is generally not achievable. Such mixedcompositions with “imperfect” distribution of constituents, however, arealso intended to be included by the term “homogeneously mixed mixture”in accordance with the present invention.

Preferably, the particles of the at least one solid particulate filler Fare distributed throughout the entire thickness of the functional layerS1. The term “distributed throughout” means that essentially allportions of the functional layer S1 contain solid filler particles butit does not necessarily imply that the distribution of the solid fillerparticles is completely uniform throughout the functional layer.

It has been found out that the concrete adhesion strength of thewaterproofing system depends, at least partly, on the surface roughness,in particular on surface waviness, of the functional layer S1.

The term “concrete adhesion strength of a waterproofing system”designates in the present document the average peel resistance [N/50 mm]per unit width of the waterproofing system upon peeling thewaterproofing system from a surface of a concrete specimen, which hasbeen casted on the surface of the functional layer and hardened for 28days under standard atmosphere (air temperature 23° C., relative airhumidity 50%).

The term “waviness” refers in the present document to surfaceirregularities upon which surface roughness is superimposed, whichirregularities have a significantly longer wavelength thanirregularities associated with surface roughness. The observed increaseof concrete adhesion strength is estimated to result from the ability ofthe fresh cementitious composition, such as fresh concrete, or anadhesive, applied on the surface of the functional layer to establishfurther mechanical interlocking between the functional layer S1 and thecementitious composition/adhesive upon hardening.

The waviness of a surface can be quantified using three-dimensional (3D)surface roughness parameters, which have been calculated from a wavinessprofile obtained by filtering a measured primary profile using asuitable λ_(c) and optionally λ_(f) profile filters. The 3D-surfaceroughness parameters can be determined according to ISO 25178 standard.

In particular, it was found out that the measured concrete adhesionstrength depends on the root mean square roughness of waviness (W(Sq))and on the auto correlation length of waviness (W(Sal)) of thefunctional layer S1. The terms “root mean square roughness of waviness”and “auto correlation length of waviness” designate the respective3D-surface roughness parameters calculated using the waviness profile.Furthermore, an especially strong positive correlation was found betweenconcrete adhesion strength and a waviness parameter determined as ratioof the root mean square roughness of waviness (W(Sq)) and square of theauto correlation length of waviness (W(Sal)).

Preferably, the at least one of the first and second major surfaces ofthe functional layer S1 has an Auto-correlation length of wavinessW(Sal), determined by means of the method cited in the description, ofat least 50 μm, preferably in the range of 100-1500 μm, more preferably150-1250 μm, most preferably 175-1000 μm.

It may also be preferred that at least one of the first and second majorsurfaces of the functional layer S1 has a waviness factor, determined asthe ratio of the Root mean square roughness of waviness W(Sq) to thesquare of the Auto-correlation length of waviness W(Sal), in the rangeof 1·10⁻⁶-1·10⁻², preferably 1·10⁻⁵-5·10⁻³, most preferably5·10⁻⁵-1·10⁻³, wherein the parameters W(Sq) and W(Sal) are determined bymeans of the method cited in the description.

Method for Determining the 3D-Surface Roughness Parameters of Waviness

In determination of the 3D-surface roughness parameters of waviness, thesurface geometry (primary profile) is first measured.

For measuring of the surface geometry, a sample sheet, preferably with asize of 80 mm (length)×30 mm (width), is adhered with the surface to bemeasured facing upwards to an glass sheet, preferably having a dimensionof 100 mm (length)×100 mm (width)×3 mm (thickness), to ensure acompletely planar lying of the sample sheet. A double-sided adhesivetape can be used in attaching the sample sheet to the glass sheet.

The surface geometry of the surface is measured with a 3D-lasermeasuring confocal microscope Olympus LEXT OLS4000 using the lasermodus, a 5× objective lens/magnification with 1× optical zoom, alarge-field observation with an image stitching of 25 single images anda measurement area of 1 cm² in the x-y-direction. In conducting thesurface geometry measurements, the top and bottom limit of confocalacquisition in z-direction is preferably adjusted manually in the lasermodus after adjusting the coarse and fine focus in the live color imagemodus.

The 3D-surface roughness parameters of waviness are then calculatedbased on the measured surface geometry with the Olympus LEXT OLS4000Application Version 2.1.3 software. The 3D-surface roughness parametersfor waviness are calculated using a primary dataset obtained from theoptical measurements, which has been filtered using a profile filter λchaving a value of 0.08 mm.

The functional layer S1 comprises 10-80 wt.-%, preferably 25-75 wt.-%,more preferably 30-70 wt.-%, most preferably 35-65 wt.-%, based on thetotal weight of the functional layer S1, of at least one thermoplasticpolymer P1.

Preferably, the at least one thermoplastic polymer P1 is selected fromthe group consisting of ethylene-vinyl acetate copolymer (EVA),ethylene-acrylic ester copolymers, ethylene-α-olefin co-polymers,ethylene-propylene co-polymers, polypropylene (PP), polyethylene (PE),polyvinylchloride (PVC), polyethylene terephthalate (PET), polystyrene(PS), polyamides (PA), chlorosulfonated polyethylene (CSPE), ethylenepropylene diene rubber (EPDM), and polyisobutylene (PIB). It may bepreferable that the thermoplastic polymer P1 is selected from the groupconsisting of low-density polyethylene, linear low-density polyethylene,high-density polyethylene, ethylene-vinyl acetate copolymer (EVA),ethylene-acrylic ester copolymers, ethylene-α-olefin co-polymers, andethylene-propylene co-polymers.

The functional layer S1 also comprises 10-80 wt.-%, preferably 25-75wt.-%, more preferably 30-70 wt.-%, most preferably 35-65 wt.-%, basedon the total weight of the functional layer S1, of at least one solidparticulate filler F. Preferably, the at least one solid particulatefiller F is a mineral filler selected from inert mineral fillers andmineral binders.

The term “inert mineral filler” designates mineral fillers, which,unlike mineral binders are not reactive with water, i.e. do not undergoa hydration reaction in the presence of water. Preferably the inertmineral filler is selected from the group consisting of sand, granite,calcium carbonate, clay, expanded clay, diatomaceous earth, pumice,mica, kaolin, talc, dolomite, xonotlite, perlite, vermiculite,Wollastonite, barite, magnesium carbonate, calcium hydroxide, calciumaluminates, silica, fumed silica, fused silica, aerogels, glass beads,hollow glass spheres, ceramic spheres, bauxite, comminuted concrete, andzeolites.

The term “sand” designates in the present document mineral clasticsediments (clastic rocks) which are loose conglomerates (loosesediments) of round or angular small grains, which were detached fromthe original grain structure during the mechanical and chemicaldegradation and transported to their deposition point, said sedimentshaving an SiO₂ content of greater than 50 wt.-%, in particular greaterthan 75 wt.-%, particularly preferably greater than 85 wt.-%.

By calcium carbonate as inert mineral filler is understood in thepresent document calcitic fillers produced from chalk, limestone ormarble by grinding and/or precipitation.

According to one or more embodiments, the functional layer S1 comprises10-80 wt.-%, preferably 25-75 wt.-%, more preferably 30-70 wt.-%, mostpreferably 35-65 wt.-%, based on the total weight of the functionallayer S1, of at least one inert mineral filler selected from the groupconsisting of sand, granite, calcium carbonate, clay, expanded clay,diatomaceous earth, pumice, mica, kaolin, talc, dolomite, xonotlite,perlite, vermiculite, Wollastonite, barite, magnesium carbonate, calciumhydroxide, calcium aluminates, silica, fumed silica, fused silica,aerogels, glass beads, hollow glass spheres, ceramic spheres, bauxite,comminuted concrete, and zeolites.

According to one or more embodiments, the functional layer S1 comprises10-80 wt.-%, preferably 25-75 wt.-%, more preferably 30-70 wt.-%, mostpreferably 35-65 wt.-%, based on the total weight of the functionallayer S1, of comminuted concrete.

Preferably, the mineral binder is selected from the group consisting ofhydraulic, non-hydraulic, latent hydraulic, and pozzolanic binders. Theterm “mineral binder” designates a binder, which in the presence ofwater reacts in a hydration reaction under formation of solid hydratesor hydrate phases. In particular, the term “mineral binder” refers tonon-hydrated mineral binders, i.e. mineral binders, which have not beenmixed with water and reacted in a hydration reaction.

According to one or more embodiments, the functional layer S1 comprises10-80 wt.-%, preferably 25-75 wt.-%, more preferably 30-70 wt.-%, mostpreferably 35-65 wt.-%, based on the total weight of the functionallayer S1, of at least one mineral binder selected from the groupconsisting of hydraulic, non-hydraulic, latent hydraulic, and pozzolanicbinders.

The term “hydraulic binder” designates in the present documentsubstances that harden as a result of chemical reactions with water(“hydration reactions”) and produce hydrates that are not water-soluble.In particular, the hydration reactions of the hydraulic binder takeessentially place independently of the water content. This means thathydraulic binders can harden and retain their strength even when exposedto water, for example underwater or under high humidity conditions.Examples of hydraulic binders include cement, cement clinker andhydraulic lime. In contrast, “non-hydraulic binders” such as air-slakedlime (non-hydraulic lime) and gypsum, are at least partially watersoluble and must be kept dry in order to retain their strength.

The term “gypsum” designates in the present document any known form ofgypsum, in particular calcium sulfate dehydrate, calcium sulfateα-hemihydrate, calcium sulfate β-hemihydrate, or calcium sulfateanhydrite or mixtures thereof. The term “latent hydraulic binder”designates in the present document particular type II concrete additiveswith latent hydraulic character according to DIN EN 206-1:2000. Thesematerials are calcium aluminosilicates that are not able to hardendirectly or harden too slowly when mixed with water. The hardeningprocess is accelerated in the presence of alkaline activators, whichbreak the chemical bonds in the binder's amorphous (or glassy) phase andpromote the dissolution of ionic species and the formation of calciumaluminosilicate hydrate phases. Examples of latent hydraulic bindersinclude granulated blast furnace slag.

The term “pozzolanic binders” designates in the present document inparticular type II concrete additives with pozzolanic characteraccording to DIN EN 206-1:2000. These materials are siliceous oraluminosilicate compounds that react with water and calcium hydroxide toform calcium silicate hydrate or calcium aluminosilicate hydrate phases.Pozzolanic binders include natural pozzolans such as trass andartificial pozzolans such as fly ash and silica fume.

According to one or more embodiments, the functional layer S1 comprises10-80 wt.-%, preferably 25-75 wt.-%, more preferably 30-70 wt.-%, mostpreferably 35-65 wt.-%, based on the total weight of the functionallayer S1, of cement or cement clinker.

The cement can be any conventional cement, for example, one inaccordance with the five main cement types according to DIN EN 197-1:namely, Portland cement (CEM I), Portland composite cements (CEM II),blast-furnace cement (CEM III), pozzolan cement (CEM IV) and compositecement (CEM V). These main cement types are subdivided, depending on theamount added, into an additional 27 cement types, which are known to theperson skilled in the art and listed in DIN EN 197-1. Naturally, allother cements that are produced according to another standard are alsosuitable, for example, according to ASTM standard or Indian standard. Tothe extent that reference is made here to cement types according to DINstandard, this naturally also relates to the corresponding cementcompositions which are produced according to another cement standard.

According to one or more embodiments, the functional layer S1 comprises1-60 wt.-%, preferably 2.5-55 wt.-%, more preferably 5-50 wt.-%, mostpreferably 10-40 wt.-%, of at least one inert mineral filler selectedfrom the group consisting of sand, granite, calcium carbonate, clay,expanded clay, diatomaceous earth, pumice, mica, kaolin, talc, dolomite,xonotlite, perlite, vermiculite, Wollastonite, barite, magnesiumcarbonate, calcium hydroxide, calcium aluminates, silica, fumed silica,fused silica, aerogels, glass beads, hollow glass spheres, ceramicspheres, bauxite, comminuted concrete, and zeolites, and 1-60 wt.-%,preferably 2.5-55 wt.-%, more preferably 5-50 wt.-%, most preferably10-40 wt.-%, of at least one mineral binder selected from the groupconsisting of hydraulic, non-hydraulic, latent hydraulic, and pozzolanicbinders, in particular cement and cement clinker, all proportions beingbased on the total weight of the functional layer S1.

According to one or more embodiments, the functional layer S1 comprises1-60 wt.-%, preferably 2.5-55 wt.-%, more preferably 5-50 wt.-%, mostpreferably 10-40 wt.-%, of comminuted concrete and 1-60 wt.-%,preferably 2.5-55 wt.-%, more preferably 5-50 wt.-%, most preferably10-40 wt.-%, of at least one other inert mineral filler and/or at leastone mineral binder selected from the group consisting of hydraulic,non-hydraulic, latent hydraulic, and pozzolanic binders, in particularcement and cement clinker, all proportions being based on the totalweight of the functional layer S1.

In case the solid particulate filler F contained in the functional layerS1 comprises or consists of mineral binders, it is preferable that thesemineral binders remain in a substantially non-hydrated state at leastuntil the functional layer S1 is contacted with a composition containingwater, such as with a fresh cementitious composition. In case thefunctional layer S1 contains hydrated mineral binders, for example, ifcomminuted concrete is used as solid particulate filler, it is essentialthat these do not form interconnected solid network of hydrated mineralbinders. The presence of such solid networks of hydrated mineral bindersin the functional layer S1 would significantly reduce the flexibility ofthe waterproofing system and also have a negative impact on the concreteadhesion strength. It has been found that the mineral binders containedin the functional layer S1 remain in a substantially non-hydrated stateeven if the waterproofing system is stored for several weeks at normalroom temperature and relative humidity of 50%.

The at least one solid particulate filler F is preferably in the form offinely divided particles. The term “finely divided particles” refers toparticles, whose median particle size d₅₀ does not exceed 500 μm. Theterm median particle size d₅₀ refers to a particle size below which 50%of all particles by volume are smaller than the d₅₀ value.

Preferably, the median particle size d₅₀ of the at least one solidparticulate filler F is 1.0-300.0 μm, more preferably 1.5-250.0 μm, evenmore preferably 2.0-200.0 μm, most preferably 2.0-150.0 μm. It may bepreferable that less than 40 wt.-%, more preferably less than 30 wt.-%,even more preferably less than 20-wt.-%, most preferably less than 10wt.-% of the particles of the at least one solid particulate filler Fhave a particle size of less than 5 μm and/or that less than 40 wt.-%,more preferably less than 30 wt.-%, even more preferably less than20-wt.-%, most preferably less than 10 wt.-% of the particles of the atleast one solid particulate filler F have a particle size of above 100μm.

Preferably, the overall particle size of the solid particulate filler F(of at least 98% of the particles) is below 250 μm, more preferablybelow 200 μm, even more preferably below 100 μm.

It has also been found that the concrete adhesion strength of thewaterproofing system is further improved by the presence of at least onesurfactant in the functional layer S1. The term “surfactant” refers inthe present document to surface tension lowering substances, which areusually organic compounds containing both hydrophobic and hydrophilicgroups. Based on the charge of the hydrophilic group the surfactants areclassified to anionic, cationic, amphoteric, non-ionic surfactants.

It is believed that the presence of surfactants in the functional layerS1 lowers the surface tension of water contained in a fresh cementitiouscomposition, which further enhances the ability of the freshcementitious composition to wet the surface of the functional layer S1and to form an interlocking mechanical bond between the waterproofingsystem and the cementitious composition upon hardening.

According to one or more embodiments, the functional layer S1 furthercomprises at least one surfactant SF selected from the group consistingof anionic, cationic, amphoteric, non-ionic, and polymeric surfactants.

Examples of suitable anionic surfactants include surfactants containingcarboxylate, sulfate, phosphate or sulfonate groups, such as amino acidderivatives; fatty alcohol ether sulfates; fatty alcohol sulfates;soaps; alkylphenol ethoxylates; fatty alcohol ethoxylates;alkanesulfonates; olefinsulfonates; and alkyl phosphates.

Examples of suitable cationic surfactants include quaternary ammonium orphosphonium compounds, such as, for example, tetraalkylammonium salts;N,N-dialkylimidazoline compounds; dimethyldistearylammonium compounds,N-alkylpyridine compounds; and ammonium chlorides.

Amphoteric (zwitterionic) surfactants have both cationic and anioniccenters attached to the same molecule. Examples of suitable amphotericsurfactants include amphoteric electrolytes such as aminocarboxylic acidand betaines.

Examples of suitable non-ionic surfactants include ethoxylates, such as,for example, ethoxylated adducts of alcohols, such as polyoxyalkylenepolyols; amines; fatty acids; fatty acid amides; alkylphenols;ethanolamides; fatty amines; polysiloxanes; fatty acid esters; alkyl oralkylphenyl polyglycol ethers, such as, for example, fatty alcoholpolyglycol ethers; alkylglycosides; sugar esters; sorbitan esters;polysorbates or trialkylamine oxides; esters and amides ofpoly(meth)acrylic acids with polyalkylene glycols or aminopolyalkyleneglycols, which at most may be tacked at one end with alkyl groups.

Polymeric surfactants can be divided into two groups of compounds. Thefirst group includes comb or rake polymers where there is an organicpolymeric chain with hydrophobic groups at regular intervals along thechain and hydrophilic groups at random or regular intervals along thatchain. The second group of polymeric surfactants includes blockco-polymers where there are blocks of hydrophobic groups (B) and blocksof hydrophilic groups (A) usually in A-B-A configuration. Certainpolymeric surfactants such as ethylene oxide-propylene oxide co-polymersurfactants can also be classified as non-ionic surfactants.

Increasing the amount of the at least one surfactant SF in thefunctional layer S1 increases the ability of a fresh cementitiouscomposition to wet the surface of the functional layer S1, which enableshigher concrete adhesion strength. The surfactants, however, also have atendency to migrate from the functional layer S1 towards the interphasebetween the functional layer and the hardened cementitious composition.In case the amount of the at least one surfactant SF in the functionallayer S1 is increased above a certain threshold limit, the hydration ofcement grains is inhibited in the cementitious composition resulting ina very weak or non-existent adhesion between the functional layer S1 andthe cementitious composition after hardening.

Preferably, the at least one surfactant SF is present in the functionallayer S1 in a total amount of at least 0.05 wt.-%, based on the totalweight of the functional layer S1. It may be advantageous that the atleast one surfactant SF is present in the functional layer S1 in a totalamount of 0.05-5.0 wt.-%, preferably 0.1-4.0 wt.-%, more preferably0.1-3.0 wt.-%, most preferably 0.25-2.0 wt.-%, based on the total weightof the functional layer S1.

Preferably, the at least one surfactant SF is selected from the groupconsisting of glycerol monostearates, polycarboxylate ethers,polyether-modified polysiloxanes, polyalkylene oxide siloxanes,hydroxyethyl amines, erucamides, stearyl stearamides, alkali metalalkanesulfonates, and alkyl aryl sulfonates.

Examples of suitable commercially available glycerol monostearatesinclude Dimodan HP (from Danisco).

Examples of suitable polycarboxylate ethers include polycarboxylateether-based superplasticizers (PCEs), which are composed by amethoxy-polyethylene glycol copolymer (side chain) grafted withmethacrylic acid copolymer (main chain). Suitable commercially availablepolycarboxylate ether-based superplasticizers include Viscocrete®Polymer PC-2, Viscocrete® Polymer RMC-2, and Cemerol® R-750 MC (fromSika).

Examples of suitable polyether-modified polysiloxanes includepolyetherpolysiloxane copolymers. Suitable commercially availablepolyether-modified polysiloxanes include Tegostab B8870 (from Evonik).

Examples of suitable commercially available polyalkylene oxide siloxanesinclude Niax L-1500 (from Momentive).

Examples of suitable hydroxyethyl amines include bis(2-hydroxyethyl)amines, which are commercially available as Armostat 300 (from AkzoNobel).

Examples of suitable commercially available erucamides and stearylstearamides include Kemamide E180 and Kemamide S180 (from PMC Biogenix).

Examples of suitable alkali metal alkanesulfonates include sodiumalkanesulfonates, which are commercially available as Armostat 3002(from Akzo Nobel) and Loxiol 93P (from Emery Oleochemicals).

Examples of suitable commercially available alkylarylsulfonates includeZetaSphere 2300, 3100 and 3700 (from Airproducts).

According to one or more embodiments, the functional layer S1 comprisesat least one surfactant SF selected from the group consisting ofglycerol monostearates, polycarboxylate ethers, polyether-modifiedpolysiloxanes, polyalkylene oxide siloxanes, hydroxyethyl amines,erucamides, stearyl stearamides, alkali metal alkanesulfonates, andalkyl aryl sulfonates, wherein the at least one surfactant SF is presentin the functional layer S1 in a total amount of 0.05-5.0 wt.-%,preferably 0.1-4.0 wt.-%, more preferably 0.1-3.0 wt.-%, most preferably0.25-2.0 wt.-%, based on the total weight of the functional layer S1.

In waterproofing applications, one of the important characteristics isthe strength of adhesion by which a waterproofing system is bonded to asubstrate, for example a concrete surface, to be sealed against waterpenetration. In case the strength of adhesion is too low, gaps are moreeasily formed between the system and the surface of the substrate, whichmay lead to loss of water tightness.

Preferably, the waterproofing system has concrete adhesion strength ofat least 5 N/50 mm, more preferably at least 10 N/50 mm, even morepreferably of at least 15 N/50 mm, most preferably of at least 20 N/50mm. In particular, the waterproofing system may have concrete adhesionstrength in the range of 5-300 N/50 mm, preferably of 10-250 N/50 mm,more preferably of 15-200 N/50 mm, most preferably of 20-200 N/50 mm.

In the context of the present invention, the concrete adhesion strengthof a waterproofing system is determined using the measurement methoddescribed below.

Method for Determining the Concrete Adhesion Strength of a WaterproofingSystem

For the measurement of the average peel resistance, a concrete testspecimen having a waterproofing system adhered on its surface using aconcrete composition is first prepared.

A sample strip with dimensions of 200 mm (length)×50 mm (width) is firstcut from the waterproofing system. One edge of the sample strip on theside of the functional layer is covered with an adhesive tape having alength of 50 mm and a width coinciding with the width of the samplewaterproofing system to prevent the adhesion to the hardened concrete.The adhesive tapes are used to provide easier installation of theconcrete test specimens to the peel resistance testing apparatus. Thesample strip is then placed into a formwork having a dimension of 200 mm(length)×50 mm (width)×30 mm (height) with the functional layer facingupwards and the barrier layer, if present, facing the bottom of theformwork.

For the preparation of the concrete specimen, a fresh concreteformulation is prepared by mixing 92.06 wt.-% of a concrete dry batch oftype MC 0.45 with 7.73 wt.-% of water and 0.21 wt.-% of Sikament-12S forfive minutes in a tumbling mixer. The concrete dry batch of type MC 0.45contains 17.21 wt.-% of CEM I 42.5 N cement (preferably Normo 4, Holcim)and 74.84 wt.-% of aggregates containing 3.0 wt.-% of Nekafill-15 (fromKFN) concrete additive (limestone filler), 24.0 wt.-% of sand having aparticle size of 0-1 mm, 36.0 wt.-% of sand having a particle size of1-4 mm, and 37 wt.-% of gravel having a particle size of 4-8 mm. Beforeblending with water and Sikament-12S the concrete dry batch ishomogenized for five minutes in a tumbling mixer.

The formwork containing the sample strip is subsequently filled with thefresh concrete formulation and vibrated for two minutes to release theentrapped air. After hardening for one day the concrete specimen isstripped from the formwork and stored under standard atmosphere (airtemperature 23° C., relative air humidity 50%) for 28 days beforemeasuring the average peel resistance.

The average peel resistance upon peeling the sample strip from thesurface of the concrete specimen is measured using a Zwick RoellAllroundLine Z010 material testing apparatus equipped with a Zwick Roell90°-peeling device or using a similar testing apparatus fulfilling therequirements of the DIN EN 1372 standard.

In the peel resistance measurement, the concrete specimen is clampedwith the upper grip of the material testing apparatus for a length of 10mm at the end of the concrete specimen comprising the taped section ofthe sample strip. Following, the sample strip is peeled off from thesurface of the concrete specimen at a peeling angle of 90° and at aconstant cross beam speed of 100±10 mm/min. During the peel resistancemeasurement the distance of the rolls is preferably approximately 570mm. The peeling of the sample strip is continued until a length ofapproximately 140 mm of the sample strip is peeled off from the surfaceof the concrete specimen. The average peel resistance is calculated asaverage peel force per unit width of the strip [N/50 mm] during peelingover a length of approximately 70 mm thus excluding the first and lastquarter of the total peeling length from the calculation.

There are no particular restrictions for the thickness of the functionallayer S1. The suitable thickness of the functional layer S1 depends onthe intended field of application and on the build-up of thewaterproofing system. Typically, functional layers with a thickness ofabove 25 mm are not practical, at least not for use as waterproofingmembranes or roofing membranes. On the other hand, functional layerswith a thickness of below 10 μm have been found to be difficult toproduce, at least with the desired surface roughness/waviness of thefunctional layer. The functional layer S1 may have a thickness of atleast 0.05 mm, in particular 0.05-15.0 mm, preferably 0.1-10.0 mm, morepreferably 0.1-5.0 mm, even more preferably 0.25-2.5 mm, most preferably0.35-2.5 mm.

The preferred thickness of the functional layer S1 also depends on thebuild-up of the waterproofing system, for example on the number oflayers contained in the waterproofing system. In case the waterproofingsystem comprises, in addition to the functional layer S1, at least oneother layer, such as a barrier layer, the thickness of the functionallayer may be at least 0.05 mm, in particular 0.05-10.0 mm, preferably0.05-5.0 mm, more preferably 0.1-2.5 mm, even more preferably 0.2-2.5mm, most preferably 0.25-2.0 mm.

In case the waterproofing system consists essentially of functionallayer the S1, in particular if the waterproofing system does notcomprise any other layers, in particular thermoplastic barrier layers,the thickness of the functional layer may be at least 0.1 mm, preferably0.1-15.0 mm, more preferably 0.25-10.0 mm, even more preferably 0.35-7.5mm, most preferably 0.5-5.0 mm.

In the context of the present invention, the thickness of the functionallayer S1 is determined by using a measurement method as defined in DINEN 1849-2 standard. An optical microscope, such as of type KeyenceVHX-600 with 30-fold magnification, can be used for measuring thethicknesses of the layer cross sections.

In order to improve the mechanical properties of the functional layerS1, it can be advantageous that the functional layer S1 is reinforcedwith a layer of fiber material bonded to at least one of its majorsurfaces. The reinforcement layer can be in the form of a fiber mat, afiber-woven fabric or a fibrous tissue. Particularly suitable materialsfor the reinforcement layer include glass fibers, polyester fibers andnylon fibers. It may be advantageous that the functional layer S1comprises a first and second reinforcement layers bonded to the firstand second major surfaces of the functional layer S1, respectively.

According to one or more embodiments, the waterproofing system furthercomprises a barrier layer S2 having a first major surface and a secondmajor surface, wherein the barrier layer S2 comprises at least onethermoplastic polymer P2, and wherein the second major surface of thefunctional layer S1 and the first major surface of the barrier layer aredirectly connected to each other over at least parts of their areas.

The functional layer S1 and the barrier layer S2 are sheet-like elementshaving first and second major surfaces defined by peripheral edges. Theexpression “directly connected” is understood to mean in the context ofthe present invention that no further layer or substance is presentbetween the layers, and that the opposing surfaces of the two layers aredirectly bonded to each other or adhere to each other. At the transitionarea between the two layers, the materials forming the layers can alsobe present mixed with each other.

The thickness of the barrier layer S2 is not subjected to any particularrestrictions. However, waterproofing systems comprising a barrier layerhaving a thickness of above 15 mm or below 10 μm are usually notpractical in waterproofing applications. The thickness of the barrierlayer S2 may be at least 0.05 mm, preferably in the range of 0.05-15.0mm, more preferably 0.1-7.5 mm, most preferably 0.2-5.0 mm. Thethickness of the barrier layer can be determined using the method asdefined in EN 1849-2 standard.

According to one or more embodiments, the waterproofing system furthercomprises a barrier layer S2 having a first major surface and a secondmajor surface, wherein the barrier layer S2 comprises at least onethermoplastic polymer P2, and wherein the second major surface of thefunctional layer S1 and the first major surface of the barrier layer aredirectly connected to each other over at least parts of their areas, anda second functional layer S1′ having a first major surface and a secondmajor surface, wherein the first major surface of the second functionallayer S1′ and the second major surface of the barrier layer S2 aredirectly connected to each other over at least parts of their areas, andwherein the second functional S1′ layer comprises:

a) 10-80 wt.-%, preferably 25-75 wt.-%, of at least one thermoplasticpolymer P1′,

b) 10-80 wt.-%, preferably 25-75 wt.-%, of at least one solidparticulate filler F′, said proportions being based on the total weightof the second functional layer S1′, and wherein

in the second functional layer S1′, the particles of the at least onesolid particulate filler F′ are dispersed in a continuous thermoplasticphase comprising the at least one thermoplastic polymer P1′,

Preferably, the second major surface of the second functional layer S1′has a waviness factor, determined as the ratio of the Root mean squareroughness of waviness W(Sq) to the square of the Auto-correlation lengthof waviness W(Sal), in the range of 1·10-6-1·10-2, preferably1·10-5-5·10-3, most preferably 5·10-5-1·10-3, wherein the parametersW(Sq) and W(Sal) are determined by means of the method cited in thedescription.

According to one or more embodiments, the second functional layer S1′further comprises at least one surfactant SF′, which is present in thesecond functional layer S1′ in a total amount of at least 0.05 wt.-%,based on the total weight of the second functional layer. It may beadvantageous that the at least one surfactant SF′ is present in thesecond functional layer S1′ in a total amount of 0.05-5.0 wt.-%,preferably 0.1-4.0 wt.-%, more preferably 0.1-3.0 wt.-%, most preferably0.25-2.0 wt.-%, based on the total weight of the second thermoplasticcomposition.

Any kind of thermoplastic polymer is in principle suitable to be used inthe functional layers S1 and S1′ and in the barrier layer S2. Suitablethermoplastic polymers P1, P1′, and P2 can have a melting point, forexample, in the range of 25-250° C., preferably 55-225° C., morepreferably 60-200° C., most preferably 65-150° C. The term “meltingpoint” refers in the present document to the maximum of the curvedetermined according to ISO 11357 standard by means of dynamicdifferential calorimetry (DSC). At the melting point the materialundergoes transition from the solid to the liquid state. Themeasurements can be performed with a Mettler Toledo 822e device at aheating rate of 2 degrees centigrade/min and the melting point valuescan be determined from the measured DSC curve with the help of the DSCsoftware.

The glass transition temperature (T_(g)) of the thermoplastic polymersP1, P1′, and P2 is preferably below the temperatures occurring duringthe use of the waterproofing system. It is therefore preferred that theT_(g) of the at least one thermoplastic polymers P1, P1′, and P2 isbelow 0° C., more preferably below −15° C., most preferably below −30°C. The term “glass transition temperature” refers in the presentdocument to the temperature measured by DSC according to ISO 11357standard above which temperature a polymer component becomes soft andpliable, and below which it becomes hard and glassy. The measurementscan be performed with a Mettler Toledo 822e device at a heating rate of2 degrees centigrade/min and the T_(g) values can be determined from themeasured DSC curve with the help of the DSC software.

Preferably, the at least one thermoplastic polymer P1, the at least onethermoplastic polymer P1′, and the at least one thermoplastic polymer P2are selected from the group consisting of ethylene-vinyl acetatecopolymer (EVA), ethylene-acrylic ester copolymers, ethylene-α-olefinco-polymers, ethylene-propylene co-polymers, polypropylene (PP),polyethylene (PE), polyvinylchloride (PVC), polyethylene terephthalate(PET), polystyrene (PS), polyamides (PA), chlorosulfonated polyethylene(CSPE), ethylene propylene diene rubber (EPDM), and polyisobutylene(PIB). It may be preferable that the thermoplastic polymers P1, P1′, andP2 are selected from the group consisting of low-density polyethylene,linear low-density polyethylene, high-density polyethylene,ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic estercopolymers, ethylene-α-olefin co-polymers, and ethylene-propyleneco-polymers.

Preferably, the at least one thermoplastic polymer P1 and P1′ aremiscible with the at least one thermoplastic polymer P2. Morepreferably, the at least one thermoplastic polymer P1 and P1′ areweldable with the at least one thermoplastic polymer P2. The polymersbeing “weldable” with each other means here that a thermoplastic layerconsisting of the thermoplastic polymer P1 or P1′ can be homogenouslyjoined by heat welding with another thermoplastic layer consisting ofthe thermoplastic polymer P2. According to one or more embodiments, thefunctional layer S1 contains only one thermoplastic polymer P1, thesecond functional layer S1′ contains only one thermoplastic polymer P1′,and the barrier layer contains only one thermoplastic polymer P2, whichthermoplastic polymers P1, P1′, and P2 are identical.

The preferences given above for the at least one solid particulatefiller F and to the at least one surfactant SF apply equally to the atleast one solid particulate filler F′ and to the at least one surfactantSF′.

The functional layer S1 and the second functional layer S1′ cancomprise, in addition to the at least one thermoplastic polymer P1 andP1′, the at least one solid particulate filler F and F′, and the atleast one surfactant SF and SF′, respectively, additives such as UV- andheat stabilizers, antioxidants, plasticizers, flame retardants, dyes,pigments such as titanium dioxide and carbon black, matting agents,antistatic agents, impact modifiers, biocides, and processing aids suchas lubricants, slip agents, antiblock agents, and denest aids

The barrier layer S2 can comprise, in addition to the at least onethermoplastic polymer P2, additives such as UV- and heat stabilizers,antioxidants, plasticizers, flame retardants, dyes, pigments such astitanium dioxide and carbon black, matting agents, antistatic agents,impact modifiers, biocides, and processing aids such as lubricants, slipagents, antiblock agents, and denest aids.

The preferences given above for the at least one thermoplastic polymerP1, P1′, and P2, for the at least one solid particulate filler F and F′,and for the at least one surfactant SF and SF′, apply equally to allaspects of the present invention unless otherwise stated.

Another subject of the present invention is a method for producing awaterproofing system comprising a functional layer S1 having a firstmajor surface and a second major surface, the method comprising steps ofextruding and/or calendaring a first thermoplastic composition to formsaid functional layer S1, and subjecting at least one of the first andsecond major surfaces of the functional layer S1 to a mechanical surfacetreatment step selected from the group consisting of grinding, brushing,and abrasive blasting, wherein the first thermoplastic compositioncomprises:

a) 10-80 wt.-%, preferably 25-75 wt.-%, of at least one thermoplasticpolymer P1,

b) 10-80 wt.-%, preferably 25-75 wt.-%, of at least one solidparticulate filler F, said proportions being based on the total weightof the first thermoplastic composition.

The term “mechanical surface treatment” refers in the present documentany surface treatment involving a change in texture of the surface,which may involve removal of some amount of material.

Brushing can be conducted using any conventional brushes such as platebrushes, tool brushes, tube brushes, spiral brushes, circular brushes,belt brushes, roller brushes, and wire brushes. Suitable brushes to beused for mechanical surface treatment are equipped with bristles havingsufficient stiffness to enable the modification of the surface texture.It may be preferred that the bristles have a flexural modulus measuredaccording to ISO 178: 2001 of at least 2500 MPa, preferably at least3000 MPa. Particularly suitable materials for the bristles includemetallic materials such as brass, phosphor bronze, carbon steel, andstainless steel, and plastics, preferably thermoset plastics.

Grinding can be conducted using any conventional grinding tool such asgrinding wheel, cutter thread, sanding wheel, sand paper, buffer, file,preferably a grinding wheel or cutter thread, in particular a cutterthread.

The term “abrasive blasting” refers in the present document topropelling a stream of abrasive blasting material, typically solidparticles, against a surface to be treated under high pressure to modifythe surface texture. A pressurized fluid or a centrifugal wheel is usedto propel the blasting material. The abrasive blasting can be conductedas dry blasting, typically using compressed air as the blasting medium,or as wet blasting. Wet blasting is accomplished by injecting theblasting material into a pressurized water stream or creating a slurryof blasting material and water that is pressurized or introduced into acompressed air stream.

Suitable blasting materials include metal particles, synthetic mineralparticles such as glass and ceramics, natural mineral particles such ascorundum and sand, synthetic organic particles, such as comminutedplastic, natural organic particles, such as walnut shells and corncobs,and particles of ice and dry-ice.

Preferably, the mechanical surface treatment step is selected from thegroup consisting of grinding and abrasive blasting, preferably dryabrasive blasting. Due to ease of industrial scale application, it maybe preferable that the mechanical surface treatment is abrasiveblasting, preferably dry abrasive blasting, which is conducted using ablasting material selected from the group consisting of corundum,aluminum, steel, copper, metal alloys, slag, glass beads, glass pearls,glass powder, silicon oxide, silicon carbide, calcium carbonate,magnesium carbonate, sodium bicarbonate, sodium hydrogen carbonate, andplastic.

Preferably, the blasting material has median particle size d₅₀ in therange of 10-1000 μm, more preferably 10-750 μm, most preferably 25-500μm. It may be preferable to use a relatively hard blasting material, forexample blasting material having a Mosh hardness of 3-9, preferably 4-9,most preferably 5-9. It may also be possible to use softer blastingmaterials, such as those having a Mosh hardness of not more than 6, forexample not more than 5, in particular not more than 4.

The first thermoplastic composition comprises 10-80 wt.-%, preferably25-75 wt.-%, more preferably 30-70 wt.-%, most preferably 35-65 wt.-%,based on the total weight of the first thermoplastic composition, of atleast one thermoplastic polymer P1.

The first thermoplastic composition also comprises 10-80 wt.-%,preferably 25-75 wt.-%, more preferably 30-70 wt.-%, most preferably35-65 wt.-%, based on the total weight of the first thermoplasticcomposition, of at least one solid particulate filler F. Preferably, theat least one solid particulate filler F is a mineral filler selectedfrom inert mineral fillers and mineral binders.

According to one or more embodiments, the first thermoplasticcomposition comprises 10-80 wt.-%, preferably 25-75 wt.-%, morepreferably 30-70 wt.-%, most preferably 35-65 wt.-%, based on the totalweight of the first thermoplastic composition, of at least one inertmineral filler selected from the group consisting of sand, granite,calcium carbonate, clay, expanded clay, diatomaceous earth, pumice,mica, kaolin, talc, dolomite, xonotlite, perlite, vermiculite,Wollastonite, barite, magnesium carbonate, calcium hydroxide, calciumaluminates, silica, fumed silica, fused silica, aerogels, glass beads,hollow glass spheres, ceramic spheres, bauxite, comminuted concrete, andzeolites.

According to one or more embodiments, the first thermoplasticcomposition comprises 10-80 wt.-%, preferably 25-75 wt.-%, morepreferably 30-70 wt.-%, most preferably 35-65 wt.-%, based on the totalweight of the first thermoplastic composition, of at least one mineralbinder selected from the group consisting of hydraulic, non-hydraulic,latent hydraulic, and pozzolanic binders.

According to one or more embodiments, the first thermoplasticcomposition comprises 1-60 wt.-%, preferably 2.5-55 wt.-%, morepreferably 5-50 wt.-%, most preferably 10-40 wt.-%, of at least oneinert mineral filler selected from the group consisting of sand,granite, calcium carbonate, clay, expanded clay, diatomaceous earth,pumice, mica, kaolin, talc, dolomite, xonotlite, perlite, vermiculite,Wollastonite, barite, magnesium carbonate, calcium hydroxide, calciumaluminates, silica, fumed silica, fused silica, aerogels, glass beads,hollow glass spheres, ceramic spheres, bauxite, comminuted concrete, andzeolites, and 1-60 wt.-%, preferably 2.5-55 wt.-%, more preferably 5-50wt.-%, most preferably 10-40 wt.-%, of at least one mineral binderselected from the group consisting of hydraulic, non-hydraulic, latenthydraulic, and pozzolanic binders, in particular cement and cementclinker, all proportions being based on the total weight of the firstthermoplastic composition.

According to one or more embodiments, the first thermoplasticcomposition comprises 10-80 wt.-%, preferably 25-75 wt.-%, morepreferably 30-70 wt.-%, most preferably 35-65 wt.-%, based on the totalweight of the first thermoplastic composition, of comminuted concrete.

According to one or more embodiments, the first thermoplasticcomposition comprises 1-60 wt.-%, preferably 2.5-55 wt.-%, morepreferably 5-50 wt.-%, most preferably 10-40 wt.-%, of comminutedconcrete and 1-60 wt.-%, preferably 2.5-55 wt.-%, more preferably 5-50wt.-%, most preferably 10-40 wt.-%, of at least one other inert mineralfiller and/or a least one mineral binder selected from the groupconsisting of hydraulic, non-hydraulic, latent hydraulic, and pozzolanicbinders, in particular cement and cement clinker, all proportions beingbased on the total weight of the first thermoplastic composition.

According to one or more embodiments, the first thermoplasticcomposition further comprises at least one surfactant SF, which ispresent in the first thermoplastic composition in a total amount of atleast 0.05 wt.-%, based on the total weight of the first thermoplasticcomposition. It may be advantageous that the at least one surfactant SFis present in the first thermoplastic composition in a total amount of0.05-5.0 wt.-%, preferably 0.1-4.0 wt.-%, more preferably 0.1-3.0 wt.-%,most preferably 0.25-2.0 wt.-%, based on the total weight of the firstthermoplastic composition.

In case the first thermoplastic composition contains one or more mineralbinders, the amount of water contained in the first thermoplasticcomposition, which may be present therein, for example, as physicalblowing agent, should be low enough to keep the mineral binders inessentially non-hydrated form during the melt-processing andextrusion/calendering steps. Hydration of the mineral binders during theproduction process is not desired since it would significantly reducethe flexibility of the functional layer S1 due to the formation ofinterconnected solid networks of hydrated mineral binders. Flexibilityof the functional layer S1 is essential in order to providewaterproofing systems, which can be stored and transported in form ofrolls and which can be easily applied on the surface of the substrate tobe waterproofed. Hydration of mineral binders may also decrease theconcrete adhesion strength of the waterproofing system.

According to one or more preferred embodiments, the amount of water inthe first thermoplastic composition is not more than 5 wt.-%, preferablynot more than 2.5 wt.-%, more preferably not more than 1 wt.-%, mostpreferably not more than 0.5 wt.-%, based on the total weight of thefirst thermoplastic composition.

Preferably, the method for producing a waterproofing system comprises afurther step of employing space apart calendar cooling rolls throughwhich the formed functional layer S1 is drawn immediately following theextrusion or calendering steps.

Extrusion Process

Preferably, an extrusion apparatus comprising at least one extruder anda die is used for extruding the first thermoplastic composition in themethod for producing the waterproofing system. Such extrusionapparatuses are well known to a person skilled in the art. A suitableextruder comprises a barrel and a screw unit contained in the barrel ora ram. Any conventional extruders, for example, a ram extruder, singlescrew extruder, or a twin-screw extruder may be used. Preferably, theextruder is a screw extruder, more preferably a twin-screw extruder. Thescrew unit of a conventional screw extruder is typically considered tocomprise feed, transition, and metering sections. In the feed sectionthe thermoplastic composition enters the channels of the rotating screwand is conveyed towards the transition section, in which the compositionis compressed and melted. The composition should be fully melted when itleaves the transition section. The function of the metering section isto homogenize the melted composition and to allow it to be metered orpumped out at constant rate. The extruder apparatus further comprises adie, preferably a flat die, consisting of manifold, approach, and lipregions. In case of a co-extrusion process, the extruder apparatuscomprises at least two extruders, preferably twin-screw extruders, and asingle manifold or a multi manifold die.

The extruder barrel comprises a feed port through which the material tobe extruded is fed to the extruder and an outlet port through which thematerial leaves the barrel. The outlet port is coupled with the die viaa gate or adapter piece. A mixing device may be interposed between thebarrel and the die. The feed port is generally connected with a hopperto which the material to be extruded is added. It is preferred that ascreen pack and a breaker plate are positioned at the end of the barrelto avoid plugging in the nozzles. The extruder further comprises heatingelements, cooling elements, temperature sensors and temperature controlelements to provide temperature controlled zones along the barrel, alsoknown as barrel zones. The extruder may comprise, for example, 3 to 8barrel zones, preferably at least 5 barrel zones, by the use of which atemperature profile can be realized in the barrel.

Preferably, a significant part, preferably the entire amount of the atleast one thermoplastic polymer P1 is fed into the extruder through thefeed port. It may be preferred that at least part of the at least onesolid particulate filler F is fed into the extruder through another portlocated downstream from the feed port. The term “downstream” designatesin the present document the direction to the outlet port. For example,it may be advantageous that not more than 50 wt.-%, preferably not morethan 30 wt.-%, more preferably not more than 10 wt.-%, of the totalamount of the at least one solid particulate filler F is fed into theextruder through the feed port with the entire amount of the at leastone thermoplastic polymer P1 and the remaining portion of the at leastone solid particulate filler F is fed into the extruder through aanother port located downstream from the feed port. It may also bepreferable that only a portion of the at least one surfactant SF is fedto the extruder through the feed port and that at least 10 wt.-%,preferably at least 20 wt. % is fed into the extruder through anotherport located downstream from the feed port.

Some or all of the constituents of the first thermoplastic compositioncan also be mixed to obtain a premix, which is then fed into theextruder through the feed port. The premix can be carried out using ablending apparatus, which are known to a person skilled in the art. In apremixing process, the particles of the at least one thermoplasticpolymer P1 are mixed at an elevated temperature with the otherconstituents, such as with the at least one solid particulate filler Fto obtain a homogeneously mixed mixture. It is also possible to thatsome or all of the constituents of the first thermoplastic compositionare processed in a compounding extruder to pellets or granules, whichare fed into extruder though the feed port.

The extrusion temperature is preferably 80-250° C., more preferably100-240° C., even more preferably 120-220° C., most preferably 140-200°C. The term “extrusion temperature” refers to the temperature of theextruded composition in the die outlet. Preferably, the extrusionpressure is 20-350 bar, preferably 30-240 bar, more preferably 35-200bar, most preferably 40-130 bar. The “extrusion pressure” refers to thepressure of the composition at the end of the metering zone just beforethe composition enters the die inlet.

The extrusion process may be conducted by using different temperatureprofiles, such as an increasing temperature profile where thetemperature increases downstream the barrel, a decreasing temperatureprofile where the temperature decreases downstream the barrel, and ahumped temperature profile where the temperature increases from the feedport toward a certain set point, for example toward the middle of thebarrel.

According to one or more embodiments, the waterproofing system furthercomprises a barrier layer S2 having a first and a second major surfacesand wherein the method comprises steps of:

i) Co-extruding the first thermoplastic composition and a secondthermoplastic composition comprising at least one thermoplastic polymerP2 through a common die to form a composite article, wherein the firstthermoplastic composition forms the functional layer S1 and the secondthermoplastic composition forms the barrier layer S2,ii) Employing spaced apart calender cooling rolls through which theformed composite article is drawn immediately following step i),iii) Subjecting the major surface of the functional layer S1 not bondedto the barrier layer S2 to a mechanical surface treatment step selectedfrom the group consisting of grinding, brushing, and abrasive blasting.

In this embodiment, a co-extruder comprising a first extruder for thefirst thermoplastic composition and a second extruder for the secondthermoplastic composition and a die, preferably a flat die, is used. Thefirst thermoplastic composition and the second thermoplasticcompositions are extruded through the common die, which can be equippedwith single or multi manifold, to simultaneously form the functionallayer S1 and the barrier layer S2. The thickness of the extrudedfunctional layer S1 and barrier layer S2 as well as the adhesion betweenthe layers can be easily controlled by adjusting the die lip of theextruder apparatus and/or by adjusting the gap size between the calendercooling rolls.

The functional layer S1 and the barrier layer S2 are sheet-like elementshaving first and second major surfaces defined by peripheral edges. Inthe formed composite article, the functional layer S1 and the barrierlayer S2 are directly connected to each other over at least parts oftheir opposing major surfaces.

Alternatively to the co-extrusion process, a waterproofing systemcomprising a functional layer S1 and a barrier layer S2 can be producedusing two extruder apparatuses each comprising an extruder and a die,preferably a flat die. In this embodiment, the method for producing awaterproofing system comprises steps of:

i) Extruding the first thermoplastic composition using a first extrusionapparatus to form said first functional layer S1,

ii) Extruding a second thermoplastic composition comprising at least onethermoplastic polymer P2 using a second extrusion apparatus to form saidbarrier layer S2,

iii) Bonding the formed first functional layer S1 to the formed barrierlayer S2 to form a composite article,

iv) Employing a spaced apart calender cooling rolls through which theformed composite article is drawn immediately following step iii),

v) Subjecting the major surface of the functional layer S1 not bonded tothe barrier layer S2 to a mechanical surface treatment step selectedfrom the group consisting of grinding, brushing, and abrasive blasting.

The formed functional layer S1 and barrier layer S2 can be bonded toeach other using any conventional means such as calendering rolls orlamination wheels to form the composite article. Alternatively, thesecond thermoplastic composition comprising the at least onethermoplastic polymer P2 can be extruded directly on the surface of theformed functional layer S1 by using the second extrusion apparatus. Inthis case, the barrier layer S2 is simultaneously formed and bonded tothe previously formed functional layer S1. It is also possible that thefirst thermoplastic composition is extruded directly on the surface ofthe formed barrier layer S2 using the extrusion apparatus. In this case,the functional layer S1 is simultaneously formed and bonded to thepreviously formed barrier layer S2.

According to one or more embodiments, the waterproofing system furthercomprises a barrier layer S2 having a first and a second major surfaceand a second functional layer S1′ having a first and second majorsurface, and the method comprises steps of:

i) Co-extruding the first thermoplastic composition and a secondthermoplastic composition comprising at least one thermoplastic polymerP2 through a common die to form a two-layer composite article, whereinthe first thermoplastic composition forms the first functional layer andthe second thermoplastic composition forms the barrier layer S2,ii) Extruding a third thermoplastic composition using an extrusionapparatus to form said second functional layer S1′,iii) Bonding the formed second functional layer S1′ to said two-layercomposite article to form a three-layer composite article,iv) Employing spaced apart calender cooling rolls through which theformed three-layer composite article is drawn immediately following stepiii),v) Subjecting the major surface of the functional layer S1 and/or themajor surface of the functional layer S1′ not bonded to the barrierlayer S2 to a mechanical surface treatment step selected from the groupconsisting of grinding, brushing, and abrasive blasting.

In the obtained three-layer composite article, the second major surfaceof the functional layer S1 and the first major surface of the barrierlayer S2 are directly connected to each other over at least parts oftheir areas and the second major surface of the barrier layer S2 and thefirst major surface of the second functional layer S1′ are directlyconnected to each other over at least parts of their areas.

Alternatively, the three-layer composite article comprising the firstfunctional layer S1, the barrier layer S2, and the second functionallayer S1′ can be formed by co-extruding the first thermoplasticcomposition, the second thermoplastic composition, and the thirdthermoplastic composition through a common die. In this embodiment, aco-extrusion apparatus comprising a first extruder for the firstthermoplastic composition, a second extruder for the secondthermoplastic composition, and a third extruder for the thirdthermoplastic composition, is used. The first, second and thirdthermoplastic compositions are melt-processed in the extruders andsimultaneously extruded through the common die, which can be equippedwith single or multi manifold. The thickness of the extruded layers S1,S2, and S1′ as well as the adhesion between the layers can be easilycontrolled by adjusting the die lip of the co-extruder apparatus and/orby adjusting the gap size between the calender cooling rolls.

Preferably, the third thermoplastic polymer composition comprises:

a) 10-80 wt.-%, preferably 25-75 wt.-%, of at least one thermoplasticpolymer P1′,

b) 10-80 wt.-%, preferably 25-75 wt.-%, of at least one solidparticulate filler F′.

According to one or more embodiments, the third thermoplasticcomposition further comprises at least one surfactant SF′, which ispresent in the third thermoplastic composition in a total amount of atleast 0.05 wt.-%, based on the total weight of the third thermoplasticcomposition. It may be advantageous that the at least one surfactant SF′is present in the third thermoplastic composition in a total amount of0.05-5.0 wt.-%, preferably 0.1-4.0 wt.-%, more preferably 0.1-3.0 wt.-%,most preferably 0.25-2.0 wt.-%, based on the total weight of thirdthermoplastic composition.

The first thermoplastic composition and the third thermoplasticcompositions can comprise, in addition to the at least one thermoplasticpolymer P1 and P1′, the at least one solid particulate filler F and F′,and the at least one surfactant SF and SF′, respectively, additives suchas UV- and heat stabilizers, antioxidants, plasticizers, flameretardants, dyes, pigments such as titanium dioxide and carbon black,matting agents, antistatic agents, impact modifiers, biocides, andprocessing aids such as lubricants, slip agents, antiblock agents, anddenest aids

The second thermoplastic composition can comprise, in addition to the atleast one thermoplastic polymer P2, additives UV- and heat stabilizers,antioxidants, plasticizers, flame retardants, dyes, pigments such astitanium dioxide and carbon black, matting agents, antistatic agents,impact modifiers, biocides, and processing aids such as lubricants, slipagents, antiblock agents, and denest aids.

Another subject of the present invention is a single or multiple layerwaterproofing system obtainable by using the method according to thepresent invention.

Another subject of the present invention is use of a mechanical surfacetreatment step selected from the group consisting of grinding, brushing,and abrasive blasting, to increase the waviness factor of a surface of afunctional layer S1 comprising:

a) 10-80 wt.-%, preferably 25-75 wt.-%, of at least one thermoplasticpolymer P1,

b) 10-80 wt.-%, preferably 25-75 wt.-%, of at least one solidparticulate filler F, said proportions being based on the total weightof the functional layer S1, wherein

the waviness factor is determined as the ratio of the Root mean squareroughness of waviness W(Sq) to the square of the Auto-correlation lengthof waviness W(Sal), and wherein the parameters W(Sq) and W(Sal) aredetermined by means of the method cited in the description.

Preferably, in the functional layer S1, the particles of the at leastone solid particulate filler F are dispersed in a continuousthermoplastic phase comprising the at least one thermoplastic polymerP1.

Still another subject of the present invention is a method forwaterproofing a substrate. The substrate can be any structural or civilengineering structure, which is to be sealed against moisture and water.The surface of the substrate can be orientated horizontally or not.

In case the waterproofing system does not comprise a barrier layer S2,the method for waterproofing a substrate comprises steps of:

-   -   applying a waterproofing system according to the present        invention to a surface of a substrate such that a first major        surface of the functional layer S1 is directed against the        surface of the substrate,    -   casting a fresh cementitious composition on a second major        surface of the functional layer S1, and    -   hardening the fresh cementitious composition.

In case the waterproofing system comprises a functional layer S1 and abarrier layer S2, the method for waterproofing a substrate comprisessteps of:

-   -   applying a waterproofing system according to the present        invention to a surface of a substrate such that the second major        surface of the barrier layer S2 facing away from the functional        layer S1 is directed against the surface of the substrate,    -   casting a fresh cementitious composition on the first major        surface of the functional layer S1 facing away from the barrier        layer S2, and    -   hardening the fresh cementitious composition.

Preferably, the fresh cementitious composition is a fresh concretecomposition.

The casted cementitious composition after hardening can be part of astructure, in particular, an above-ground or underground structure, forexample a building, garage, tunnel, landfill, water retention, pond,dike or an element for use in pre-fabricated constructions.

Still another subject of the present invention is a waterproofedconstruction for waterproofing a substrate against water penetration.

In case the waterproofing system does not comprise a barrier layer S2,the waterproofed construction comprises a layer of concrete and awaterproofing system according to the present invention arranged betweenthe surface of the substrate and the layer of concrete such that thefirst major surface of the functional layer S1 is directed against thesurface of the substrate and the second major surface of the functionallayer S1 is fully bonded to the surface of the layer of concrete.

In case the waterproofing system comprises a functional layer S1 andbarrier layer S2, the waterproofed construction comprises a layer ofconcrete and a waterproofing system according to the present inventionarranged between the surface of the substrate and the layer of concretesuch that the second major surface of the barrier layer S2 facing awayfrom the functional layer S1 is directed against the surface of thesubstrate and the first major surface of the functional layer S1 facingaway from the barrier S2 layer is fully bonded to the surface of thelayer of concrete.

The term “fully bonded” refers in the present document to two surfacesbeing adhesively joined over the full surface.

The substrate can be any structural or civil engineering structure,which is to be sealed against moisture and water, such as a hardenedconcrete structure or a subsurface.

EXAMPLES

The materials shown in Table 1 were used in the examples.

TABLE 1 Materials used in the experiments Trade name CompositionProvider Polymer 1 *EVA copolymer with 19 wt.-% Eni Polimeri Europa ofvinyl acetate Surfactant Surface active anionic Emery Oleochemicalscompound Cement CEM II/B-M (T-LL) 42,5 N SN LaFargeHolcim EN 197-1cement *EVA, ethylene vinyl acetate copolymer

Preparation of the Waterproofing Systems

The exemplary and reference double-layer waterproofing systems Ex1-Ex5and Ref-1 comprising a functional layer and a barrier layer wereproduced using a laboratory scale co-extrusion apparatus comprising twotwin screw extruders (Berstorff GmbH), a flat die and set ofwater-cooled calender rolls. A thermoplastic membrane based on EVA-LLDPEpolymer blend was used as the barrier layer in all double-layerwaterproofing systems.

A first mixture containing the constituents of the functional layer anda second mixture containing the constituents of the barrier layer weremelt-processed in a first and second twin screw extruders andco-extruded through a common flat die on top of each other to produce adouble-layer membrane, which was subsequently cooled between thecalender rolls. The gap between the calender cooling rolls was adjustedto be somewhat smaller than the total thickness of the extruded membraneto bond the layers together. The thickness of the functional layers wasapproximately 0.5 mm and the thickness of the barrier layer wasapproximately 0.7 mm.

The compositions of the functional layers and operating conditions ofthe co-extrusion apparatus during production of the double-layerwaterproofing systems are presented in Table 2. The extrusiontemperature and pressure were measured at a point, where themelt-processed mass entered the inlet of the flat die. The temperatureof the cooling rolls was approximately 20° C. during the productionprocess.

Surface Treatment Method

The surface texture of each functional layer of a tested waterproofingsystem was modified by using different mechanical treatment techniques.

In Ex1 and Ex5 the surface of the functional layer was treated by usinga standard thread cutter tool of type ¼ NC20 and of type ½ NC13,respectively. In this treatment method, a sample strip of eachwaterproofing system with the functional layer facing outward was firstwrapped (spanned) around a metal tube having a diameter of 15 cm. Thesurface of the functional layer was then grinded by using the threadcutter tool attached to a hand held electric drill. The revolution speedof the cutter thread was set to 500 rpm/min and the tool was moved backand forth, mainly in lengthwise direction of the surface, with anapproximate speed of 15-20 cm/s. The pressure directed to the surfacewith the tool varied between 7.5 and 9.5 N.

In Ex2 the surface of the functional layer was brushed by hand using awire brush having dimensions of 40 mm (width) and 105 mm (length). Thebristles (total amount 1200) of the brush were made of stainless steeland had a diameter of 0.25 mm. In this treatment, a strip of thewaterproofing system lying flat on a workbench with the functional layerfacing upwards was brushed with stroking movements from the bottom tothe top using relatively high pressure. The pressure applied to thesurface with the wire brush varied between 30 and 60 N.

In Ex3 the surface of the functional layer was grinded using a grindingwheel having a grain size of 200-500 μm (grit size 40) until ahomogeneous abrasion pattern was obtained. The functional layer wasgrinded by hand using circular movements while pressing the grindingwheel against the surface with a moderate pressure.

In Ex4 the surface of the functional layer was subjected to abrasiveblasting using Lepco Micropeen 1100 ZP/ZPD blasting unit and corundumparticles having average particles size 250-350 μm. Before the blastingtreatment, a sample strip of the waterproofing system with thefunctional layer facing outward was wrapped (spanned) around a metaltube having a diameter of 15 cm. The corundum particles were blastedagainst the functional layer using a pressure of 5 bar, a jet distanceof 10 cm, and a jet angle of 45°. The length of time period required totreat a surface having size of approximately 200 mm×300 mm wasapproximately 2 min.

Measurement of Thickness of the Layers

The thicknesses of the functional and barrier layers were determined byusing a measurement method as defined in DIN EN 1849-2 standard. Anoptical microscope of type Keyence VHX-600 with 30-fold magnificationwas used for measuring the thickness of the cross sections.

Measurement of 3D-Surface Roughness Parameters for Waviness

For measuring the surface geometry of the functional layers, a samplemembrane with a size of 100 mm (length)×100 mm (width) was cut from eachexample membrane and adhered to an aluminum sheet having a dimension of100 mm (length)×100 mm (width)×5 mm (height), with the functional layerfacing upwards, to ensure a completely planar lying of the sample. Adouble-sided adhesive tape was used in attaching the sample to thealuminum sheet.

The surface geometry of each functional layer was measured with a3D-laser measuring confocal microscope Olympus LEXT OLS4000 using thelaser modus, a 5× objective lens/magnification with 1× optical zoom, alarge-field observation with an image stitching of 25 single images anda measurement area of 1 cm2 in the x-y-direction. In conducting thesurface geometry measurements, the top and bottom limit of confocalacquisition in z-direction was adjusted manually in the laser modusafter adjusting the coarse and fine focus in the live color image modus.

The 3D-surface roughness parameters for waviness were calculated fromthe measured surface geometry with the attached Olympus LEXT OLS4000Application Version 2.1.3 software. The 3D-surface roughness parametersW(Sq) and W(Sal) were calculated from a filtered primary datasetobtained from the optical measurements using a cutoff length λc=0.08 mm.The 3D-surface roughness parameters for waviness shown in Table 2 havebeen obtained as average from at least two measurements conducted atdifferent locations on the surface of a functional layer of each samplemembrane.

Preparation of the Concrete Test Specimen

Three sample strips with a dimension of 200 mm (length)×50 mm (width)were cut from each of the example waterproofing systems Ex 1-Ex 6produced as described above. The sample strips were placed intoformworks having a dimension of 200 mm (length)×50 mm (width)×30 mm(height) with the functional layer facing upwards and with the barrierlayer against the bottom of the formwork.

One edge of each sample strip on the side of the functional layer wascovered with an adhesive tape having a length of 50 mm and widthcoinciding with the width of the strip to prevent the adhesion to thehardened concrete. The adhesive tapes were used to provide easierinstallation of the test specimens to the peel resistance testingapparatus.

For the preparation of concrete specimens a batch of fresh concreteformulation was prepared. The fresh concrete formulation was obtained bymixing 8.9900 kg of a concrete dry batch of type MC 0.45 conforming toEN 1766 standard, 0.7553 kg of water and 0.0202 kg of Sikament-12S forfive minutes in a tumbling mixer. The concrete dry batch of type MC 0.45contained 1.6811 kg of CEM I 42.5 N cement (Normo 4, Holcim), 7.3089 kgof aggregates containing 3% Nekafill-15 (from KFN) concrete additive(limestone filler), 24% sand having a particle size of 0-1 mm, 36% sandhaving a particle size of 1-4 mm, and 37% gravel having a particle sizeof 4-8 mm. Before blending with water and Sikament-12S the concrete drybatch was homogenized for five minutes in a tumbling mixer.

The formworks containing the sample strips were subsequently filled withthe fresh concrete formulation and vibrated for two minutes to releasethe entrapped air. After hardening for one day the test concretespecimens were stripped from the formworks and stored under standardatmosphere (air temperature 23° C., relative air humidity 50%) beforemeasuring the peel resistances.

Measurement of Concrete Peel Resistances

The measurement of peel resistances was conducted in accordance with theprocedure laid out in the standard DIN EN 1372:2015-06. A Zwick RoellAllroundLine Z010 material testing apparatus equipped with a Zwick Roell90°-peeling device (type number 316237) was used for conducting the peelresistance measurements.

In the peel resistance measurements, a concrete specimen was clampedwith the upper grip of the material testing apparatus for a length of 10mm at the end of the concrete specimen comprising the taped section ofthe sample strip. Following, the strip was peeled off from the surfaceof the concrete specimen at a peeling angle of 90° and at a constantcross beam speed of 100 mm/min. During the measurements the distance ofthe rolls was approximately 570 mm.

The peeling of the sample strip was continued until a length ofapproximately 140 mm of the strip was peeled off from the surface of theconcrete specimen. The values for peel resistance were calculated asaverage peel force per width of the sample strip [N/50 mm] duringpeeling over a length of approximately 70 mm thus excluding the firstand last quarter of the total peeling length from the calculation.

The average peel resistance values for the example waterproofing systemsEx1-Ex5 presented in Table 2 have been calculated as an average of threemeasurements conducted with the same waterproofing system.

TABLE 2 Functional layer composition Ref-1 Ex1 Ex2 Ex3 Ex4 Ex5 Polymer 149 49 49 49 49 49 Surfactant 1 1 1 1 1 1 Cement 50 50 50 50 50 50Co-extruder conditions 1^(st) extruder pressure, [bar] 98 98 98 98 98 981^(st) extruder temperature, [° C.] 168 168 168 168 168 168 1^(st)extruder flux, [kg/h] 10.5 10.5 10.5 10.5 10.5 10.5 2^(nd) extruderpressure, [bar] 90 90 90 90 90 90 2^(nd) extruder temperature, [° C.]180 180 180 180 180 180 2^(nd) extruder flux, [kg/h] 20.4 20.4 20.4 20.420.4 20.4 Functional layer thickness, [mm] 0.5 0.5 0.5 0.5 0.5 0.5Surface treatment None Thread Wire brush Grinding Abrasive Thread cutterfine wheel blasting cutter rough Surface properties W(Sq) 38.64 228.2315.64 10.48 32.37 176.62 W(Sal) 5.02 635.15 645.21 401.69 188.52 896.32Waviness factor 1.535 5.657 · 10⁻⁰⁴ 3.757 · 10⁻⁰⁵ 6.492 · 10⁻⁰⁵ 9.106 ·10⁻⁰⁴ 2.198 · 10⁻⁰⁴ Concrete peel resistance 0 31 13 18 35 20 (after 28d), [N/50 mm]

The invention claimed is:
 1. A method for producing a waterproofingsystem comprising (i) a functional layer S1 having a first major surfaceand a second major surface, and (ii) a barrier layer S2 having a firstmajor surface bonded to the second major surface of the functional layerS1, the first major surface of the functional layer S1 being not bondedto the barrier layer S2, the method comprising: a least one of extrudingand calendering a first thermoplastic composition to form the functionallayer S1; and subjecting the first major surface of the functional layerS1 to a mechanical surface treatment step selected from the groupconsisting of grinding, brushing, and abrasive blasting, wherein thefirst thermoplastic composition comprises: a) 10-80 wt.-%, of at leastone thermoplastic polymer P1, and b) 10-80 wt.-%, of at least one solidparticulate filler F, the proportions being based on a total weight ofthe first thermoplastic composition.
 2. The method according to claim 1,wherein an amount of water in the first thermoplastic composition is notmore than 10 wt.-%, based on the total weight of the first thermoplasticcomposition.
 3. The method according to claim 1, further comprisingemploying spaced apart calender cooling rolls through which the formedfunctional layer S1 is drawn immediately following the at least one ofthe extrusion and calendering step.
 4. The method according to claim 1,wherein the barrier layer S2 has a second major surface, and the methodfurther comprises: i) co-extruding the first thermoplastic compositionand a second thermoplastic composition comprising at least onethermoplastic polymer P2 through a common die to form a compositearticle, the first thermoplastic composition forming the functionallayer S1 and the second thermoplastic composition forming the barrierlayer S2, and ii) employing spaced apart calender cooling rolls throughwhich the formed composite article is drawn immediately following stepi).
 5. The method according to claim 1, wherein the barrier layer S2 hasa second major surface, and the method further comprises: i) extrudingthe first thermoplastic composition using a first extrusion apparatus toform the first functional layer S1, ii) extruding a second thermoplasticcomposition comprising at least one thermoplastic polymer P2 using asecond extrusion apparatus to form the barrier layer S2, iii) bondingthe formed first functional layer S1 to the formed barrier layer S2 toform a composite article, and iv) employing spaced apart calendercooling rolls through which the formed composite article is drawnimmediately following step iii).
 6. The method according to claim 1,wherein the barrier layer S2 has a second major surface, and thewaterproofing system further comprises and a second functional layer S1′having a first and second major surface, and the method furthercomprises: i) co-extruding the first thermoplastic composition and asecond thermoplastic composition comprising at least one thermoplasticpolymer P2 through a common die to form a two-layer composite article,the first thermoplastic composition forming the first functional layerand the second thermoplastic composition forming the barrier layer S2,ii) extruding a third thermoplastic composition using an extrusionapparatus to form the second functional layer S1′, the thirdthermoplastic composition comprising: a) 10-80 wt.-%, of at least onethermoplastic polymer P1′, b) 10-80 wt.-%, of at least one solidparticulate filler F′, the proportions being based on a total weight ofthe third thermoplastic composition, iii) bonding the formed secondfunctional layer S1′ to the two-layer composite article to form athree-layer composite article, iv) employing spaced apart calendercooling rolls through which the formed three-layer composite article isdrawn immediately following step iii), v) subjecting the major surfaceof the functional layer S1′ not bonded to the barrier layer S2 to amechanical surface treatment step selected from the group consisting ofgrinding, brushing, and abrasive blasting.
 7. The method according toclaim 1, wherein at least one of the first and second major surfaces ofthe functional layer S1 has an auto-correlation length of wavinessW(Sal) of at least 50 μm.